Thomas me do



(No Model.)

T. MGDONOUG'H.

GAS ENGINE. No. 315,808. 14, 1885.

8 H muum WITNESSES: DWENTOR:

ATTORNEYS.

7 UNITED STATES *PAL'rnN'r rricn.

THOMAS MGDONOUGH, OF MOXTCLAIR', NEXV JERSEY.

GAS-ENGINE.

SPECIFICATION ioriniag part of Letters Patent No. 315,808, dated April14, 1885.

Application filed November 11, 1884. (No model) To ctZZ whom it mayconcern:

Be it known that I, Tnonas MoDoNoUGH, of Montclair, in the county ofEssex and State of New Jersey, have invented a new and usefulImprovement in Gas Engines, of which the following isafull, clear, andexact description.

Reference is to he had to the accompanying drawings, forming a part ofthis specification, in which similar letters of reference indicatecorresponding parts in all the figures.

Figure 1 is a sectional side elevation of one of my improvedgas-engines. Fig. 2 is a side elevation, partlyin section, of the sameturned one-quarter around from the position shown in Fig. 1. Fig. 3 is aplan view of the lower end of the lower or short piston, the pistonrodsbeing shown in section. Fig. at is a front elevation of the upper end ofthe piston-rod of the lower piston. Fig. 5 is a side elevation of thesame.

The object of this invention'is to provide gasengines constructed insuch a manner as to economize heat and power, and thus obtain betterresults than are attainable with gasengines constructed in the ordinarymanner.

The invention consists in the construction and arrangement of parts, aswill be hereinafter fully described and claimed.

A is the engine-cylinder, which is made with an open lower end, and isattached at the said lower end to a supporting-frame, B. The cylinder Ais prolonged upward for a distance equal to about two diameters of thesaid cylinder. The upward extension A of the cylinder A is made so muchlarger than the lower part as to form space for a firebrick lining, O,andleave theinnersurface of the said lining flush with the inner surfaceof the lower part, A, of the cylinder, as shown in Figs. 1 and The partA of the cylinder forms the combustion-chamber, and by this constructionthe engine is less expensive in manufacture than when thecombustion-chamber is made separate and is bolted to the cylinder. Bythis construction, also, the shell of the coinbustion-chainber A can hemade so thin at its junction with the cylinder A that there will be butlittle conduct-ion of heat through it to the said cylinder A. Inthelower part of the cylinder A is formed an inletport, D, to admit gas,and in the upper part of the combustion-chamber A is formed anexhaust-port, E,

for the escape of the spent gas, which ports are provided, respectively,with valves F G, the stems of which are connected with the same rod H,so that both valves will be operated at the same time and by the samemechanism. The lower end of the rod H is connected with an eccentric, I,formed upon or attached to the driving-shaft J, so that the valves F Gwill be opened and closed ateach revolution of the said shaft J. Theshaft J revolves in hearings in the frame B, and is provided with abalance-wheel, K, to give steadiness of 1110- tion to the variousoperating parts of the enine.

3 In the COlllbllStlOlhChitlllbCl A, near its up per end, is formed aport, L, through which ignition of the gas takes place, and which isprovided with a valve, M, for controlling the said ignition. The valveBI is provided with an ignition gas-jet, N, and a relighting gas-jet, O.The stem of the valve M is connected with the upper end of a rod, 1, thelower end of which is connected with an eccentric, Q, formed upon orattached to the shaft J, so that the said valve will be opened andclosed ateach revolution of the said shaft.

In the cylinder A A. are placed two pistons, It S, the upper one, R, ofwhich is made long, is provided with a central longitudinal perforation,T, and with a valve, U, opening upward at the lower end of the saidperforation to allow the gas to pass upward freely and prevent itsreturn.

To the lower end of the long piston R is attached the upper end'ot' apiston-rod, V, which passes through the lower piston, S, and through aguidebea-ring in a bar of the frame B, and to its lower end is pivotedthe lower end of the connecting-rod W. The upper end of theconnecting-rod W is pivoted to the end of the long arm of an elbow, X,which is pivoted at its angle to a support attached to the frame B, andto the end of its short arm is pivoted one end of the shortconnecting-rod Y. The other end of the connecting-rod Y is pivoted tothe crank Z, formed upon or attached to the shaft J. To the crank Z isalso pivoted the lower end of the piston-rod a, the upper end of whichis forked to pass around the piston-rod I, and is hinged to lugs formedupon the lower end of the short lower piston, S. The pistons R S can beconnected with the shaft J by the mechi the end of its inward stroke,and will keep the piston R close to the piston S during most of itsoutward stroke. The gas is introduced through the port D into thecylinder A between the pistons R S, and passes up through the valve Uand the perforationl. into the combustion-chamber A, whence, afterignition and expansion, the spent gas escapes through the .exhaust-portE, the various movements and the action of the gas being as follows:Whenthelong piston R begins to move away from the piston S, the gasenters the space betweenthem through the inlet-port D,'-and at the sametime the spent gas'from the previous ignition is driven out through theexhaustport E by the said upward movement of the long piston It. Thenthe long piston R moves downward and theshort piston S moves inwardsimultaneously, the gas is compressed, opens the valve U, and passesthrough the perforation T into the combustion-chamber. When the shortpiston S is at the end of its inward stroke and the long piston It isnearly ineontact with it, the gas is ignited-and expands, forcing thepistons R S outward and completing thecycle ofmovements. By thisarrangement the gas is introduced into a cold cylinder, compressed, andthen transferred to a hot chamber, whereit is fired, expanded, andexhausted ateach revolution of the shaft. An ordinary-water-jacket maybe used, if desired; but when the engineis set vertically the-downwardconduction of heat is so little as not-to'afiect the lower partof'the'cylinder.

Having thus describedmy invention, I claim as new and desire to secureby Letters Patent-- 1. In agas-engine, the combination, with thecylinder A, closed at its upper end to form a combustion-chamber, andopen at its lower end, of the long piston R,- the short piston S, belowthe same within said cylinder, inlet, exhaust, and ignition valves, andan operating mechanism, substantially as described.

2. In a gas-engine, the combination, with the combustion-chamber A, thecylinder A, the short piston S, and an operating mechanism, of the longpiston R, substantially as herein shown and described, whereby the gaswill be compressed, ignited, expanded, and discharged at eachrevolution, as set-forth.

3. In a gas-engine, the combination, with the cylinder A, thecombustion-chamber A, the inlet-valveF, the exhaust-valve G, the ig-rnition-valve M, and the shaft J, o'f the-"connecting rods H P, and theeccentrics I Q, substantially as herein shown anddescr-ibed, whereby thesaid valves will be opened and closed at each revolution'o'f the saidshaft, as set forth.

4. In a gasengine, the combination, with the two pistons R S and theshaft'J, of the piston rods V a, the connecting-rods W Y, theelbow-lever X, and the crank Z, substantially as herein shown anddescribed, whereby'motion will be given tothe said shaft, and the saidpistons will be made to moveat theproper times and'in the the properdirections, asset JAMES T. GRAHAM, O. SEDGWICK.

